Micro-structural Change During Nucleation: From Nucleus To Bicontinuous Morphology

Although the microstructure of coexistence phase provides direct insights of the nucleation mechanism and their change is substantial in the phase transition, their study is limited due to the lack of suitable tools capturing the thermodynamically unstable transient states. We resolve this problem in computational study by introducing a generalized canonical ensemble simulation and investigate the morphological change of the nucleus during the water evaporation and condensation. We find that at very low pressure, where the transition is first order, classical nucleation theory holds approximately. A main nucleus is formed in the supersaturation near spinodal, and the overall shape of the nucleus is finite and compact. On increasing the pressure of the system, more nuclei are formed even before spinodal. They merge into a larger nuclei with a smaller free energy penalty to form ramified shapes. We suggest order parameters to describe the extent of fluctuation, and their relation to the free energy profile.

[1]  P. Fratzl,et al.  Nucleation and growth of magnetite from solution. , 2013, Nature materials.

[2]  Valeria Molinero,et al.  Water modeled as an intermediate element between carbon and silicon. , 2009, The journal of physical chemistry. B.

[3]  Aaron M. Streets,et al.  Ostwald ripening of clusters during protein crystallization. , 2010, Physical review letters.

[4]  J. Savage,et al.  Experimental evidence for two-step nucleation in colloidal crystallization. , 2009, Physical review letters.

[5]  Michele Parrinello,et al.  Freezing of a Lennard-Jones fluid: from nucleation to spinodal regime. , 2006, Physical review letters.

[6]  Dimo Kashchiev,et al.  Nucleation : basic theory with applications , 2000 .

[7]  D. Maes,et al.  Observing classical nucleation theory at work by monitoring phase transitions with molecular precision , 2014, Nature Communications.

[8]  Daan Frenkel,et al.  Quantitative prediction of crystal-nucleation rates for spherical colloids: a computational approach. , 2004, Annual review of physical chemistry.

[9]  John E Straub,et al.  Generalized replica exchange method. , 2010, The Journal of chemical physics.

[10]  Klein,et al.  Spinodal nucleation as a coalescence process. , 1992, Physical review letters.

[11]  R. Sear.  The non-classical nucleation of crystals: microscopic mechanisms and applications to molecular crystals, ice and calcium carbonate , 2012 .

[12]  Anthony K. Felts,et al.  Temperature weighted histogram analysis method, replica exchange, and transition paths. , 2005, The journal of physical chemistry. B.

[13]  D. Zahn.  How does water boil? , 2004, Physical review letters.

[14]  N. Xu,et al.  Supplementary Information for Visualizing kinetic pathways of homogeneous nucleation in colloidal crystallization , 2013 .

[15]  J. D. Yoreo,et al.  Crystal nucleation: more than one pathway. , 2013 .

[16]  Peter G Bolhuis,et al.  Interplay between structure and size in a critical crystal nucleus. , 2005, Physical review letters.

[17]  B. Trout,et al.  Nucleation from Solution , 2013, Science.

[18]  Ainhoa Berciano-Alcaraz,et al.  A computational approach of , 2010 .

[19]  Andrew Schofield,et al.  Real-Space Imaging of Nucleation and Growth in Colloidal Crystallization , 2001, Science.

[20]  Woo Jong Cho,et al.  Limit of metastability for liquid and vapor phases of water. , 2014, Physical review letters.

[21]  P. Debenedetti.  Thermodynamics: When a phase is born , 2006, Nature.

[22]  S. Aloni,et al.  In situ TEM imaging of CaCO3 nucleation reveals coexistence of direct and indirect pathways , 2014, Science.

[23]  D. Frenkel,et al.  Prediction of absolute crystal-nucleation rate in hard-sphere colloids , 2001, Nature.

[24]  B. Bagchi,et al.  Elucidating the mechanism of nucleation near the gas-liquid spinodal. , 2007, Physical review letters.

[25]  Xin Zhou,et al.  Parallel Tempering Simulation on Generalized Canonical Ensemble , 2012 .

[26]  H. Reiss,et al.  Fusion of the extended modified liquid drop model for nucleation and dynamical nucleation theory. , 2004, Physical review letters.

[27]  Deniz Erdemir,et al.  Nucleation of crystals from solution: classical and two-step models. , 2009, Accounts of chemical research.

[28]  Helmut Cölfen,et al.  Stable Prenucleation Calcium Carbonate Clusters , 2008, Science.

[29]  Pablo G. Debenedetti,et al.  A computational study of homogeneous liquid–vapor nucleation in the Lennard-Jones fluid , 1999 .

[30]  Hans Hasse,et al.  Comprehensive study of the vapour–liquid coexistence of the truncated and shifted Lennard–Jones fluid including planar and spherical interface properties , 2006 .

[31]  A. V. Van Driessche,et al.  Role of clusters in nonclassical nucleation and growth of protein crystals , 2014, Proceedings of the National Academy of Sciences.

[32]  K. Fuchizaki,et al.  Phase diagram of the modified Lennard-Jones system. , 2012, The Journal of chemical physics.

[33]  A. Lamorgese,et al.  DIFFUSE-INTERFACE MODELING OF LIQUID-VAPOR PHASE SEPARATION IN A VAN DER WAALS FLUID , 2009 .

[34]  Chin-Kun Hu,et al.  Phase diagram and universality of the Lennard-Jones gas-liquid system. , 2012, The Journal of chemical physics.

[35]  Shinji Saito,et al.  Molecular dynamics simulation of the ice nucleation and growth process leading to water freezing , 2002, Nature.